A glass ceramic sintered body containing gahnite and cordierite as crystal phases, having a thermal expansion coefficient at 40 to 400° C. of not larger than 5×10−6/° C., a dielectric constant of not larger than 7 and a Young's modulus of not larger than 150 GPa. A wiring board having an insulating substrate made of the glass ceramic sintered body features very high reliability in the primary mounting and in the secondary mounting.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A glass ceramic sintered body comprising gahnite and cordierite as crystal phases, having a thermal expansion coefficient at 40 to 400° C. of not larger than 5×10 −6/ ° C. a dielectric constant of not larger than 7 and a Young's modulus of not larger than 150 GPa. obtained by firing a mixed powder of a glass powder having the following composition: SiO 2 : 30 to 55 mass % Al 2 O 3 : 15 to 40 mass % MgO: 3 to 25 mass % ZnO: 2 to 15 mass % B 2 O 3 : 2 to 15 mass % and a filler powder, wherein the glass ceramic sintered body further comprising a CaO-containing glass phase.
2. A glass ceramic sintered body according to claim 1 , wherein the flexural strength is not smaller than 150 MPa.
3. A glass ceramic sintered body according to claim 1 , comprising PbO not larger than 0.1 mass % and an alkali metal oxide not larger than 0.1 mass.
4. A glass ceramic sintered body according to claim 1 , further comprising at least one crystal phase selected from the group consisting of alumina, spinel, mullite, anorthite, slawsonite, celsian and zirconia.
5. A glass ceramic sintered body according to claim 1 , comprising a cordierite crystal phase in an amount of not smaller than 20 mass % and having a thermal expansion coefficient at 40 to 4000° C. of not larger than 4.5×10 −6 /° C.
6. A glass ceramic sintered body according to claim 5 , comprising, as said filler powder, at least one inorganic powder for adjusting properties selected from the group consisting of mullite, anorthite, slawsonite, celsian and quartz glass, and further comprising a cordierite powder.
7. A glass ceramic sintered body according to claim 1 , further comprising alumina as a crystal phase.
8. A glass ceramic sintered body according to claim 7 , wherein the flexural strength is not smaller than 200 MPa, and a reduction in the weight of when immersed in a 1-mass % HF aqueous solution for one minute is not larger than 3 μg/mm 2 .
9. A glass ceramic sintered body according to claim 8 , wherein the filler powder comprises a CaO-releasing Ca compound powder, a cordierite powder and an alumina powder.
10. A glass ceramic sintered body according to claim 1 , further comprising, enstatite and/or forsterite as crystal phases, the content the cordierite is not smaller than 20 mass %, and the total content of the cordierite, enstatite and/or forsterite is not smaller than 40 mass %.
11. A glass ceramic sintered body according to claim 10 , wherein the flexural strength is not smaller than 200 MPa, and the filler powder comprises cordierite, enstatite and/or forsterite.
12. A wiring board having wiring layers of a low-resistance metal arranged a the front surface and/or inside of an insulating substrate made of a glass ceramic sintered body of claim 1 .
13. A wiring board according to claim 12 , wherein a semiconductor device comprising chiefly silicon is arranged on the surface of said insulating substrate.
14. A wiring board according to claim 13 , wherein a recessed portion is formed in the surface of said insulating substrate, and a semiconductor device comprising chiefly silicon is arranged in said recessed portion.
15. A mounted structure of a wiring board obtained by mounting a wiring board of claim 12 on the surface of a printed wiring board that has an insulating substrate containing an organic resin.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
October 22, 2003
October 11, 2005
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.